Metabolic effects of four intravenous nutritional regimens in patients undergoing elective surgery II.--Muscle amino acids and energy-rich phosphates.

Muscle amino acids and energy-rich phosphates have been determined in 28 patients before and after resection of a carcinoma of colon or rectum. Before operation the patients received a synthetic diet (Vivasorb for four days and postoperatively four different intravenous regimens with different amounts and proportions of amino acids were given for six days, the energy intake being the same for all groups. When compared with age-matched healthy controls the patients showed only slight increases in phenylalanine and isoleucine concentration in muscle and plasma with elevated plasma glutamate during the four days prior to the operation. Vivasorb treatment increased the concentration of alanine, glycine and methionine in both muscle and plasma while increases of threonine and histidine were seen only in muscle. Decreased concentrations of valine were found in muscle and plasma, while lysine and leucine decreased only in plasma. As an effect of operation, but independent of the nutritional regimen, muscle asparagine increased and muscle glutamine and glutamate decreased in all groups. The unique pattern of amino acid changes in postoperative trauma was confirmed in the present investigation but few differences in amino acid concentrations could be related to the various nutritional intakes. Alterations in the individual amino acid concentrations were not influenced by the intake of amino acids and seemed to have little relationship to the composition of any solution infused. Prior to operation there were low levels of ATP in muscle possibly due to immobilisation and chronic semistarvation but no changes in the energy rich phosphates could be attributed to trauma or nutrition. The content of muscle glycogen increased as a result of the Vivasorb supply indicating that the preoperative carbohydrate administration promotes muscle glycogen synthesis and postoperatively muscle glycogen was reduced significantly indicating enhanced glycogenolysis in the postoperative state. This finding emphasizes the importance of providing the patients with ample amount of glucose before and after surgery.